For some time now various people have experimented with vaporizing gasoline and mixing it with air in proper proportions for internal combustion engines. There appears to be certain advantages in completely vaporizing fuel prior to its being mixed with air. Mainly these advantages are improved fuel mixture distribution to each cylinder of an engine and more uniform fuel-air mixture; thus, a leaner air-to-fuel ratio can be successfully achieved without engine misfire. Some of the problems encountered in attempting to vaporize gasoline have been in the area of metering the correct quantities of vapor to air.
The present invention contemplates metering liquid fuel prior to the vaporizing step. There are very efficient electronic fuel metering and fuel injection systems in production at this time. The most appropriate electronic fuel injection system to be used in conjunction with the present vapor system would be a low pressure single point electronic fuel injection system. The electronic "brain" of this system receives signals from various areas of the engine, its intake and exhaust systems, as well as ambient conditions. It is proposed to use this system in conjunction with a vaporizing unit located in the throttle body. The vaporizer will consist of a small chamber wherein exhaust heat is circulated through at a calibrated rate. Exhaust temperatures and pressures are related to throttle positions and engine power output. Based on this premise, a proper or consistent vaporizing temperature can be maintained at all throttle positions and engine operating conditions.
Thus, the invention includes the use of a system for metering liquid fuel and then vaporizing the metered fuel prior to its mixing with intake air. The proposed system will operate with any single point or throttle body fuel injection system. Any system which properly meters liquid fuel according to engine demand and discharges into a throttle body can be adapted to the present system.
The liquid fuel can be metered accurately and then vaporized to achieve accurate control of fuel quantities while obtaining the advantages of gaseous fuel with an appropriate air mixture.
Other objects of the invention will be apparent in the following description and claims in which the invention is described together with details directed to persons skilled in the art to enable practice of the invention all in connection with the best mode presently contemplated for the invention.